It is commonplace that large companies and information service providers set up call centers in different geographic areas to handle telephone inquiries from customers. After receiving one such customer call, a call center normally assigns the call to an appropriate service representative, operator and/or interactive voice response (IVR) unit therein to attend to the call. For example, a customer of an information service provider may call a designated number for information, and the call is then routed to a call center where an operator can provide the customer with the desired phone numbers and addresses of particular persons and establishments, directions, movie listings, restaurant recommendations, etc.
A call center sometimes may be deluged with telephone calls such that the operators cannot answer all calls immediately after the calls come in. In that case, the calls are queued in the call center and answered in accordance with an automatic call distribution (ACD) algorithm. As a result, a caller may experience a long wait time and feel frustrated. To reduce such a wait time, techniques have been developed to route call traffic to multiple call centers to balance the load among them. One such prior art technique requires that each call received by a call center be automatically forwarded to a central switch location where a routing server identifies the call center to which the call is routed. However, this technique may actually cause a delay in answering those calls which can otherwise be answered immediately by the receiving call center. This stems from the aforementioned requirement that each call without exception needs to be forwarded to the central switch location before it is routed to a call center to be answered.
Another prior art technique involves routing overflow calls in a call center to other call centers in a predetermined sequence. That is, overflow calls in call center A are always routed to call center B, overflow calls in call center B always to call center C, and so on and so forth. An incoming call to a call center becomes an overflow call when it is queued in the call center longer than a predetermined period. However, a major shortcoming of this technique is its inflexibility to route overflow calls in a call center to any available call center not next thereto in the sequence. For example, an overflow call in call center A would be routed to call center B even if call center B has insufficient capacity to handle the call while another call center has ample capacity to handle it.
Accordingly, there exists a need for a technique for effectively identifying overflow calls in a call center, and dynamically routing the overflow call traffic to other available call centers to handle the overflow calls.